4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xin Long <lucien.xin@xxxxxxxxx>
[ Upstream commit 30877961b1cdd6fdca783c2e8c4f0f47e95dc58c ]
Commit 296d48568042 ("ipvlan: inherit MTU from master device") adjusted
the mtu from the master device when creating a ipvlan device, but it
would also override the mtu value set in rtnl_create_link. It causes
IFLA_MTU param not to take effect.
So this patch is to not adjust the mtu if IFLA_MTU param is set when
creating a ipvlan device.
Fixes: 296d48568042 ("ipvlan: inherit MTU from master device")
Reported-by: Jianlin Shi <jishi@xxxxxxxxxx>
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ipvlan/ipvlan_main.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -546,7 +546,8 @@ int ipvlan_link_new(struct net *src_net,
ipvlan->dev = dev;
ipvlan->port = port;
ipvlan->sfeatures = IPVLAN_FEATURES;
- ipvlan_adjust_mtu(ipvlan, phy_dev);
+ if (!tb[IFLA_MTU])
+ ipvlan_adjust_mtu(ipvlan, phy_dev);
INIT_LIST_HEAD(&ipvlan->addrs);
/* If the port-id base is at the MAX value, then wrap it around and
